All Name Reactions of Organic Chemistry Class 12
Be the master of organic name reactions class 12. Learn mechanisms, solve problems, and prepare for board exams and NEET/IIT-JEE. In this article we provides the most important name reactions for class 12 borad exams, NEET, IIT-JEE and other exams.
Finkelstein Reaction, Swarts Reaction, Wurtz Reaction, Fittig Reaction, Wurtz-Fittig Reaction, Ullmann Reaction (Ullmann Coupling), Dows Process, Friedel-Crafts Alkylation, Friedel-Crafts Acylation, Kolbe's Reaction (Kolbe-Schmitt Reaction), Reimer-Tiemann Reaction, Williamson Synthesis, Cumene Process, Rosenmund Reduction, Stephen Reaction, Etard Reaction, Gattermann-Koch Reaction, Clemmensen Reduction, Wolff-Kishner Reduction, Aldol Condensation, Cross Aldol Condensation, Cannizzaro Reaction, Benzoin Condensation, Haloform Reaction, Hell-Volhard-Zelinsky (HVZ) Reaction, Decarboxylation Reaction, Hunsdiecker Reaction, Hofmann Bromamide Degradation Reaction, Amides are treated with bromine in an aqueous or ethanolic solution of sodium hydroxide to produce primary amines with one carbon atom less than the parent amide, Gabriel Phthalimide Synthesis, Carbylamine Reaction (Isocyanide Test), Hinsberg's Test, Liebermann's Nitroso Reaction, Mendius Reaction, Diazotization Reaction, Sandmeyer Reaction, Gattermann Reaction, Balz-Schiemann Reaction, Coupling Reaction.
Haloalkanes and Haloarenes
Finkelstein Reaction:
Alkyl iodide is prepared from alkyl chlorides or bromides using sodium iodide in dry acetone.
Swarts Reaction:
Fluoroalkanes can be preapared by heating alkyl chlorides or bromides with metallic fluorides (e.g., AgF, Hg₂F₂, CoF₂).
Wurtz Reaction:
Alkyl halides react with metallic sodium in dry ether to form alkanes containing double the number of carbon atoms. Methane cannot be prepared by this method.
Fittig Reaction:
Aryl halides react with metallic sodium in dry ether to form biphenyl.
Wurtz-Fittig Reaction:
A mixture of an alkyl halide and an aryl halide reacts with sodium in dry ether to form an alkyl arene.
Ullmann Reaction (Ullmann Coupling):
Chlorobenzene is heated with finely divided copper powder (or copper bronze) at temperatures above 200°C, two molecules of chlorobenzene couple to form biphenyl.
Dows Process:
When chlorobenzene is heated with an aqueous solution of NaOH at 300°C and 200 atm gives sodium phenoxide which on acidification gives phenol.
Friedel-Crafts Alkylation:
Benzene or its derivatives react with alkyl halides in the presence of anhydrous AlCl₃ to form alkylbenzenes.
Friedel-Crafts Acylation:
Benzene or its derivatives react with acyl chlorides or acid anhydrides in the presence of anhydrous AlCl₃ to form aromatic ketones.
Alcohols, Phenols, and Ethers
Kolbe's Reaction (Kolbe-Schmitt Reaction):
Sodium phenoxide reacts with carbon dioxide under pressure and heat, followed by acidification, to yield salicylic acid.
Reimer-Tiemann Reaction:
Phenol reacts with chloroform in the presence of an alkali (NaOH) to introduce a −CHO group at the ortho position, forming salicylaldehyde. (If carbon tetrachloride is used, salicylic acid is formed).
Williamson Synthesis:
Used for the preparation of symmetrical and unsymmetrical ethers by reacting an alkoxide with an alkyl halide.
Cumene Process:
Oxidation of cumene (isopropylbenzene) forms cumene hydroperoxide, which on acid hydrolysis gives phenol and acetone.
Aldehydes, Ketones and Carboxylic Acids
Rosenmund Reduction:
Acyl chlorides are catalytically hydrogenated in the presence of palladium on barium sulfate (poisoned with sulfur or quinoline) to yield aldehydes.
Stephen Reaction:
Nitriles are reduced to corresponding imines with SnCl₂ and HCl, which on hydrolysis give aldehydes.
Etard Reaction:
Toluene is oxidized by chromyl chloride to a chromium complex, which on hydrolysis gives benzaldehyde.
Gattermann-Koch Reaction:
Benzene or its derivatives react with carbon monoxide and hydrogen chloride in the presence of anhydrous AlCl₃ or CuCl to give benzaldehyde or substituted benzaldehydes.
Clemmensen Reduction:
The carbonyl group of aldehydes and ketones is reduced to a −CH₂ group on treatment with zinc amalgam and concentrated hydrochloric acid.
Wolff-Kishner Reduction:
The carbonyl group of aldehydes and ketones is reduced to a −CH₂ group on treatment with hydrazine, followed by heating with potassium or sodium hydroxide in a high-boiling solvent like ethylene glycol.
Aldol Condensation:
Aldehydes and ketones containing at least one α-hydrogen atom undergo condensation in the presence of dilute alkali to form β-hydroxy aldehydes (aldols) or β-hydroxy ketones (ketols).
Cross Aldol Condensation:
Aldol condensation carried out between two different aldehydes and/or ketones.
Cannizzaro Reaction:
Aldehydes that do not have an α-hydrogen atom undergo self-oxidation and reduction (disproportionation) on treatment with concentrated alkali. One molecule is oxidized to a carboxylic acid salt, and another is reduced to an alcohol.
Benzoin Condensation:
Two aromatic aldehydes (e.g. benzaldehyde) combine to form an α-hydroxyketone (specially, benzoin) in the presence of cyanide ions (CN-).
Perkin's (Condensation) Reaction:
Condensation of an aromatic aldehyde with an acid anhydride in the presence of sodium or potassium salt of the same acid to produce α,β-unsaturated acid.
Haloform Reaction:
Compounds containing a −CH₃CO- group (or −CH₃CH(OH)− group) react with halogen and a base to form a haloform (e.g., iodoform, CHI₃) and a carboxylic acid salt.
Hell-Volhard-Zelinsky (HVZ) Reaction:
Carboxylic acids having an α-hydrogen are halogenated at the α-position on treatment with chlorine or bromine in the presence of red phosphorus to give α-halocarboxylic acids.
Decarboxylation Reaction:
Sodium salts of carboxylic acids, when heated with soda lime (NaOH + CaO), lose a carbon dioxide molecule to form alkanes.
Hunsdiecker Reaction:
Silver salts of carboxylic acid reacts with halogens to form an unstable intermediate which further undergoes thermal decarboxylation leading to the formation of a final product known as alkyl halides.
Amines
Hofmann Bromamide Degradation Reaction:
Amides are treated with bromine in an aqueous or ethanolic solution of sodium hydroxide to produce primary amines with one carbon atom less than the parent amide.
Gabriel Phthalimide Synthesis:
Primary amines can be prepared from phthalimide by this synthesis. Phthalimide reacts with ethanolic KOH to form potassium phthalimide, which then reacts with an alkyl halide to form N-alkylphthalimide which on hydrolysis yields the primary amine.
Carbylamine Reaction (Isocyanide Test):
Primary amines, when heated with chloroform and ethanolic potassium hydroxide, form isocyanides (carbylamines), which have a foul odor. (This reaction is a test for primary amines).
Hinsberg's Test:
This test is used to distinguish primary, secondary, and tertiary amines using benzene sulfonyl chloride (Hinsberg's reagent).
Liebermann's Nitroso Reaction:
This reaction is used to identify the presence of both aliphatic and aromatic secondary amines. It involves the formation of a nitrosoamine, which then reacts with phenol in the presence of sulfuric acid, producing a characteristic blue or green color.
NaNO2 + HCl → HONO + NaCl
(C2H5)2NH + HONO → (C2H5)2N−N=O + H2O
Mendius Reaction:
Nitriles (R-CN) are reduced to primary amines (R-CH2-NH2) using sodium and ethanol.
R-CN + Na + EtOH → R-CH2-NH2.
Benzene Diazonium Chloride
Diazotization Reaction:
Aromatic primary amines react with nitrous acid (prepared in situ from NaNO₂ and a mineral acid like HCl) at low temperatures (0-5∘ C) to form diazonium salts.
Sandmeyer Reaction:
Benzene diazonium chloride reacts with CuCl/HCl, CuBr/HBr, or CuCN/KCN to substitute the diazonium group with −Cl, −Br, or −CN respectively.
Gattermann Reaction:
Similar to Sandmeyer reaction, but uses copper powder and the corresponding halogen acid (HCl or HBr) to introduce −Cl or −Br.
Balz-Schiemann Reaction:
Benzene diazonium fluoroborate, upon heating, decomposes to yield fluorobenzene, nitrogen, and boron trifluoride.
Coupling Reaction:
Benzene diazonium chloride reacts with electron-rich aromatic compounds like phenols or anilines to form brightly colored azo dyes.